System of heating boilers by exhaust-steam.



PATENTED NOV. 8. 1904.

J. NADROWSKI.

SYSTEM OF HEATING BOILERS BY EXHAUST STEAM.

APPLICATION FILED SEPT. 24, 1900 3 SHEETS-SHEET 1.

N0 MODEL.

No. 774,334. PATENTED NOV. 8,1904.

J. NADROWSKI. SYSTEM OF HEATING BOILERS BY EXHAUST STEAM.

APPLICATION FILED SEPT. 24, 1900. N0 MODEL. 3 SHEETS-SHEET 2.

No. 774,334. 'PATENTED NOVLB 1904. J. NADROWSKI.

SYSTEM OF HEATING BOILERS BY EXHAUST STEAM.

APPLIQATIOH FILED SEPT. 24, 1900. N0 MODEL. 3 SEEETS-SHEBT 3.

'riences.

UNITED STATES Patented November 8, 1904.

PATENT rrrce.

SYSTEM OF HEATING BOILERS BY EXHAUST-STEAM.

SPECIFICATION forming part of Letters Patent No. 774,334, dated November8, 1904.

App1ication filed September 24, 1900. Serial No. 30,986. (No model-i Toall whmn it may concern:

Be it known that I, JOHANNES NADROWSKI, a subject of the King ofPrussia, Emperor of Germany, residing at No. 3 Hublerstrasse, Dresden,Kingdom of Saxony, German Empire, have invented a new and useful Systemof Heating Boilers by Exhaust-Steam, of which the following is aspecification.

In engines driven by superheated steam the exhaust-steam, which is moreorless superheated, possesses a temperature which is frequently higherthan that of the water in the boiler. This is more especially the casewith turbines in which the superheating of the steam can, asdemonstrated by experiments, be carried much higher than inpiston-engines, for the reason that in turbines the steam does not comein contact with parts sliding against each other and requiring to belubricated. In piston-engines the lubricant necessarily limits thesuperheat imparted to the steam to about 350 centigrade, according topresent expe- The turbineshaft, which is the only part of the turbinewhich is in frictional contact with the other parts, is only exposed toheat of the exhanst-steam, which has gener ally a temperature much lowerthan that of the superheated steam. In a steam-turbine the upper limitof temperature can in consequence be raised much above that which isadmissible in piston-engines, so that the heat can be better utilizedthan has hitherto been the case, if only care is taken to recuperate theheat of the exhaust. This recuperation of the heat of the exhaust-steamis in the case 'of turbines driven by highly-superheated steam,facilitated by the fact that such exhaust-steam is, as experience shows,still to a superheated state, and it can in consequence raise thetemperature of a liquid much higher than saturated exhaust-steam from apistonengine. If now the temperature of. the superheated exhaust-steamis higher than the temperature in the boiler, (with the de Lavalsteam-turbines, the following temperatures were observed: admissiontemperature, 350 eentigrade; exhaust, 260; boiler, 140 the heat of theexhaust, which in this example exceeds by 120 centigrade the heat of theboiler,

can be recuperated by making use of the same for evaporation of thewater.

. The accompanying drawings show how the said invention may beconveniently and advantageously carried into practice.

In the drawings, Figure 1 illustrates a longitudinal and cross sectionof a boiler fitted with the device for utilizing the superheat of the.exhauststeam.- Fig.- 2 is a longitudinal and cross section of amodification in which the feed-water heater is located inside theboiler. Fig. 3 is a side view and front view of a modification in whichthe system of heatingtubes and feed-water heater are arranged outside ofthe boiler. Fig. 4 is a longitudinal and cross section of a modificationof the arrangement shown in Figs. 1 and 3. Fig. 5 is a longitudinalvertical sectional view of a boilerfurnace, showing the turbineconnected to the same. Fig. 6 is a transverse vertical sectional view ofthe furnace shown in Fig. 5.

Like letters of reference indicate like parts throughout the figures ofthe drawings.

The steam of the boiler A is led through the pipe H to asteam-superheater H and from the superheater to a turbine H which runs agenerator H or other suitable apparatus. From the turbine superheatedexhaust-steam is led through the pipe G in a system of heating-tubes B,which is surroundedby the boiler water,- and from there to the ordinaryfeed-water heater C, so that with a well-proportioned superficial areaof this system of tubes the exhaust-steam reaches the ordinaryfeed-Water heater with a temperature nearly equal to that of the boiler,and may from there escape through the pipe K into a condenser or theatmosphere. Through the pipe I the Water for the boiler is conductedinto the heater O. V

The system of' tubes B, which takes up the superheated exhaust-steam, isin the arrangement shown in Fig. 1 located entirely in the water-spaceof the boiler A and connected to the ordinary feed-water heater 0outside of the boiler.

To reduce the external cooling of the feedwater heater, this latter may,as shown in Fig. 2, be inclosed for the greater part in the boiler, sothat a part of the system of tubes B forms also the feed-water heater.

In the arrangement shown in Fig. 3 the heater-tubes B are locatedoutside the boiler A. In this case the water-space of the boiler isconnected to the barrel D, Which surrounds tubes B, by a pipe (4, thewater which has taken up the superheat of the exhaust-steam returning tothe boiler by the pipe I). In this case, howevenas theboiler-water,which is under boiler-pressure, cannot attain a temperaturehigher than that of the boiler a part of.

this water will be evaporated and flow as steam into the boilersteam-space. In order to render it possible to raise the steam flowingthrough (6 into I) to a temperature higher than that of the boiler andthen to cause it to take from the exhaust-steam a larger amount of heat,a throttle-valve E is provided in the pipe 6 and a pump F in pipe 0,which pump serves for forcing the Water from the boiler into barrel D. 0is an ordinary feed-water heater, similar to the one shown in Fig. 4:.

Fig. 4: shows the arrangement illustrated in Fig. 1, but modified insuch a manner that the Water-space of the boiler is connected by a pipea to the casing of the system of heatingpipes, a pump F being providedin the said pipe for forcing the water to the system of pipes and also athrottling-valve E in the pipe, which connects the system D with thesteam-space.

Boilers built in accordance with this invention may be calledregenerator-boilers.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

In a system for heating boilers by exhauststeam, the combination withthe boiler, of a superheater for heating the steam from the boiler, aturbine run by the superheated steam, and means for conveying theexhaust from the turbine through the boiler at a greater temperaturethan the water of the boiler to produce steam from the water in theboiler.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

J OHANNES NADROWVSKI.

Vitnesses:

HERNANDO DE SoTo, PAUL AREAS.

